Machine for forming helical lock seam pipe



Nov. 30, 1965 HARPER MACHINE FOR FORMING HELICAL LOCK SEAM PIPE FiledDec. 6. 1961 4 Sheets-Sheet 1 INVENTOR. LAFF/E HARPER A 7'7'ORNE VS Nov.30, 1965 HARPER MACHINE FOR FORMING HELICAL LOCK SEAM PIPE Filed Dec. 6,1961 4 Sheets-Sheet 2 INVENTOR. LAFF/E HARPER ATTORNEYS Nov. 30, 1965 L.HARPER 3,220,234

MACHINE FOR FORMING HELICAL LOCK SEAM PIPE Filed Dec. 6, 1961 4Sheets-Sheet 5 FIG l8 INVENTOR. LAFF/E HARPER A 7' TORNE VS Nov. 30,1965 L. HARPER 3,220,234

MACHINE FOR FORMING HELICAL LOCK SEAM PIPE Filed Dec. 6, 1961 4Sheets-Sheet 4 INVENTOR. LAFF/E HARPER United States Patent C) 3,220,234MACHINE FOR FORMING HELICAL LOCK SEAM PIPE Laffie Harper, 1192Montgomery Ave., San Bruno, Calif. Filed Dec. 6, 1961, Ser. No. 157,35011 Claims. (Cl. 72-50) This invention relates to a machine for forminghelical lock seam pipe, and has for one of its objects the provi sion ofa machine of the above type that is provided with a simple structureenabling the machine to be adjusted, within a substantially shorter timethan has heretofore been required in other machines for the samepurpose, for making pipe of a different diameter.

Another object of the invention is the provision of improved means in amachine for making helical lock seam pipe that enables quicklyconverting the machine to the making of pipe of different diameters, andfrom metal strips of different gauges and widths.

A still further object of the invention is the provision of a machinefor making helical lock seam pipe in which a strip of metal from whichthe pipe is formed is moved longitudinally thereof between a final pairof rollers that extend at right angles to the longitudinal axis of thestrip and whose axes are in a common vertical plane, and which strip isguided toward helical form, and the seam locked, in said plane at saidrollers.

An additional object of the invention is the provision of a simplecompact machine in which the coil from which the strip that forms ahelical or spiral pipe is drawn, is supported in a position and mannerthat not only improves the balance of the machine, but that contributesto making the machine compact and to taking the stress out of the strip.

In brief, heretofore most machines of which I am aware for makinghelical lock seam pipe are provided with relatively expensive andcomplicated structure for bending and guiding the strip as it forms thehelix. Usually such structure includes a plurality of rollers or rollersin conjunction with guide plates. The assembly of such rollers or platesprovides a forming head, and the changes required for making differentdiameter pipe, using a strip of the same gauge and width takes arelatively long time, to say nothing of the changes that would berequired where a different width strip or metal of a different gauge isto be used.

In the present invention the structure is such that Within substantiallyless than ten minutes time the machine can be adjusted to making pipe ofa different diameter from the same width strip. For example, it iscustomary to fabricate pipe of from approximately four to eight inchesin diameter from a standard flat metal strip that is slightly less thansix inches in width. This metal may be of different gauges.

Provision is made in the machine hereinafter described that eliminatesthe necessity for changing rollers where a change within normal limitsis made in the gauge of metal used, and the change from one helixforming head to another for the different diameter pipe can be made inapproximately seven minutes time. Also provision is made for quicklyadjusting the final margin bending rollers, that make the final bend forthe interlocking seam forming portions, to regulate the degree of bendthat may be required for strips of different gauges.

The present machine is not restricted to making pipe of a greaterdiameter than eight inches from the same width strip. However, it isusually found to be more economical and practical to use a wider stripfor making pipe of greater diameter than eight inches. The presentmachine is readily adapted to make pipe of any practical diameter aboveeight inches.

3127203234" Patented Nov. 30, 1965 One of the important features of thepresent invention is the particular structure of the helix forming head,which head is extremely simple, economical to make, and accurately andpositively guides the strip at all points along the length of the latterwith a minimum of frictional resistance.

Other objects and advantages will appear in the description anddrawings.

In the drawings:

FIG. 1 is a top plan view of the machine.

FIG. 2 is a side elevational view of the machine, with the strip ofmetal from which the pipe is formed being shown thereon.

FIG. 3 is an enlarged, fragmentary cross sectional view through the seamlocking rollers taken along line 33 of FIG. 1.

FIG. 4 is an enlarged, fragmentary elevational view looking at the outerends of the seam locking rollers, and showing the guide shoe on the pipeforming head.

FIG. 5 is a cross sectional view taken along line 55 of FIG. 4.

FIG. 6 is a fragmentary top plan view of the pipe forming head showing aportion of the pipe as it is formed.

FIG. 7 is a fragmentary cross sectional view taken through a portion ofthe pipe showing the flange along one marginal portion of the stripbefore the formation of a seam.

FIG. 8 is an enlarged fragmentary sectional view taken through a portionof the adjacent sides of one of the three pairs of margin formingrollers.

FIGS. 9, 10, 11, respectively, are taken along lines 9-9, 10-10 and11-11 of FIG. 2 and are enlarged to show the approximate relationshipbetween the rods of the helix forming head and the flange on the stripthat forms the pipe.

FIG. 12 is an enlarged vertical fragmentary sectional view taken throughadjacent parts of the middle set of margin forming rollers, along line12-12 of FIG. 1.

FIG. 13 is a fragmentary elevational view of the final set of marginforming rollers, the strip that is being formed being shown in crosssection.

FIG. 14 is an edge elevational view of a filler ring adapted to be usedon the coil supporting drum where the coil is a narrow strip of metal.

FIGS. 15, 16, 17 are fragmentary cross sectional views takensubstantially along lines 1515, 1616 and 17-17, respectively, of FIG. 4.

FIG. 18 is an edge view of one of the lock seam form ing rollers thatmay be substituted for one of the rollers of FIG. 3 where lighter gaugemetal is to be used.

Referring to FIGS. 1, 2 the machine herein illustrated comprises ahorizontally elongated frame generally designated 1, and which framesupports three pairs of superposed rollers for rotation, which pairs,from right to left as seen in FIG. 1, are generally designated 2, 3 and4; These are the rollers that are adapted to bend the marginal portionsof the strip of sheet metal that is to form the pipe for forming theseam, and they also drive the s rip.

The upper rollers of pairs 2, 3, 4 are designated 5, 6, 7 and the lowerrollers are designated 8, '9, 10. Rollers 5, 8 are the right hand pair(FIG. 2), rollers 6, 9 the middle pair and rollers 7, 10 the left handpair.

Shafts in coaxial extension of the inner ends of these rollers (theupper ones are seen in FIG. 1) are journalled for rotation on the frame1 or in bearings carried by the frame, the shafts in extension ofrollers 5, 6, 7 being seen in FIG. 1 and designated 12, 13, 14. Theshafts for rollers 8, 9, 10 are below shafts '12, 13, 14.

Other shafts 15, 16 also rotatably supported on the frame 1 are betweenthe shafts of rollers 8, 9 and 9, 10 and these shafts and the shafts ofrollers 5-10 are connected by gears 17 (FIG. 1), for positive rotationof the pairs of rollers 2, 3, 4 for driving a strip of sheet metal 20from right to the left as seen in FIG. 2.

A shaft 21, also rotatably carried by frame 1, has a sprocket wheel 22secured thereto, which wheel, in turn, is connected with a motor 23 by asprocket chain 24. A gear 25 on said shaft 21 is in mesh with a gear 26on the shaft that carries roller 10.

Beyond or to the left of the third pair 4 of rollers 7, 10 are the seamlocking rollers, one roller 27 (FIGS. 3, 4) being positioned over a setof three rollers '28, 29, 30 that are below roller 27.

Roller 27 is secured on the outer end of a shaft 32 that is journalledfor rotation in bearings that are rigid on frame 1, and the threerollers 28-30 are rotatably carried on the outer end of a shaft 33 thatis parallel with and below shaft 32, and that is also journalled forrotation in hearings on frame 1.

The rollers 28-30 are independently supported on their own bushings, asseen in FIG. 3, so they can rotate relative to each other, as will laterbe explained.

Shafts 32, 33 are connected by corresponding gears 34 for driving theiradjacent sides in the same direction as the margin forming sets ofrollers 2, 3, 4 and a gear 35 (FIG. 1) on shaft 33 in line with gears25, 26 is in mesh with gear 25 for driving the seam locking rollers.

These seam locking rollers are at the discharge end of the machine whilethe pair 2 of margin bending rollers is at the feed end of the machine.

The helix forming head is generally designated and is positioned withits inlet and outlet ends adj a-cent to the seam locking rollers 27-30and at the side of said rollers adjacent to the third pair 4 of marginalforming rollers.

This helix forming head will be explained more in detail later on, itbeing suflicient at this time to state that it engages and guides onepreformed marginal portion of the strip 20 to guide it along a helicalpath and to lapping relation to the other preformed marginal portion ofthe strip so that the seam locking rollers will lock them together toform the seam of the helical pipe.

The main frame 1 is supported on a subframe 41 (FIG;

2) for swinging of said main frame about the vertical axis of a pivot42, which axis extends vertically through the center of the seam lockingrollers 27, 29, and at the opposite or feed end of the machine, avertical shaft 43 is rotatably carried on the main frame, having asuitable handle 44 at its upper end for manually rotating said shaft. I

The lower end of shaft 43 has a gear 45 secured thereto, which gear isin mesh with the teeth of an arcuately extending rack 46 (FIG. 1) thatis rigid with the subframe. By manually rotating shaft 43 the main framemay be swung about pivot 42 to different positions, so that the helicalpipe 47 (FIG. 6) extending away from the seam locking rollers and fromthe helix forming head 40 can move to any desired position extendingang'ularly from the main frame.

Inasmuch as substantially the entire weight of the machine is on thesubframe 41 between pivot 42 and the feed end of the machine, provisionis made for supporting the heavy strip-supporting coil 48 in a positionat the side of pivot 42 that is opposite to the feed end of the machine.An extension 50 extends from the helix forming end of frame '1longitudinally of the latter, and a shaft 51 projects laterally of saidextension and supports a drum 52 for rotation thereon, with said drum inproper alignment with the pairs of rollers 2-4.

This drum has heads 53 at its ends, and the coil 48 has a core that isof greater diameter than the external diameter of heads 53. Thus thecoil may be positioned on the drum over the outer head of the latter,without removing the drum.

At the feed end of the machine is a pair of opposed,

peripherally flanged wheels 55 secured on a shaft 56 that is supportedfor rotation on the frame 1, the said wheels being in alignment with theheads 53 of the drum 52.

The strip 20 from coil 48 is carried under, around and over the radiallyoutwardly facing annular surfaces of wheels 55 between the radiallyoutwardly projecting annular flanges 57 on said wheels and then is movedbetween a pair of parallel guide plates 58, 59 that are formed withopposed, horizontally extending grooves in their opposed sides into andthrough which grooves the marginal: portions of the strip 20 extend. Thedotted lines 60 (FIG. 1) indicate the grooves.

The level of these grooves 60 is substantially the level of the marginalforming portions of the pairs 2, 3, 4 of marginal forming rollers, andthe spacing between guide plates 58, 59 is such that the marginalportions of the strip 20 will be guided to their proper positionsbetween the sets 2, 3, 4 of the marginal forming rollers.

In the event the width of the strip 20 is to be changed, a filler ring62 (FIG. 14) of an inside diameter greater than the outer peripheraldiameter of the outer head 53 of drum 52 is slipped over said outer headand onto the drum. Rods 63 secured at one of their ends to said ring 62at points equally spaced around the ring will space the ring from theinner head of the drum the desired distance so that the space betweenthe ring 62 and the outer head 53 will be equal to the width of the newstrip.

The marginal forming rollers 5-10 are secured on the shafts carryingthem by bolts 64 on the ends of said shafts, and they are keyed to saidshafts for rotation therewith, hence they can readily be removed andothers having their marginal forming portions spaced for the new widthstrip may be substituted.

Plates 58, 59 are removably held in place on suitable supports 65 thatare bolted at one of their ends to frame 1, and their spacing can bereadily changed to accommodate the new width strip. Also wheels 55 areadjustable relative to each other on the shaft 56.

The seam locking rollers may be replaced by others if desired, wheredifferent gauge metal is used for the pipe.

The helix forming head is readily unbolted from the frame and another ofdifferent diameter substituted when a different diameter pipe is to beformed. A bolt 66 extends through a slot 68 in a block 69 that isconnected with and supports the receiving end of the helix forming head.This bolt extends into frame 1, and another bolt 67 extends through abracket 70 that is connected with the other end of the helix forminghead 40, and into frame 1. Similar structure is provided for each helixforming head with suitable bolt holes formed in the frame 1 for securingthe different helix forming heads to the frame.

Upon actuation of motor 23 and after the leading end of strip 20 hasbeen drawn from coil 48, under and over wheels 55, and through grooves60 in supporting plates 59, 58 to between the rollers of set No. 2, thesaid strip will be driven longitudinally thereof through the rollers ofpairs Nos. 2, 3, 4 and around the helix forming head to the seam lockingroller.

The helix forming head only engages the strip 20 along the flange 71that is formed along only one marginal portion of the strip. This flangeis directed downwardly by the pairs 2-4 of the margin forming rollerswhile the opposite marginal portion of the strip is formed with anupwardly opening channel 72 by the same rollers (FIG. 12).

The helix forming head guides the flange 71 into the upwardly openingchannel, and both the flange and the sides of the channel are similarlyslightly inclined relative to vertical (FIG. 5) so that the seam lockingrollers will force said flange and said sides to horizontally positionedtight interlocking relation to form the seam 73 (FIG. 3).

Once the seam is locked the helical pipe 47 will be continuously formedas long as the strip 20 is fed through the machine.

These operations, in themselves, are generally performed by conventionalhelical pipe forming machines.

The specific combinations, structures and methods that are particularlyimportant in the present machine will now be considered separately.

Coil, frame and strip feed structure and arrangement As has been brieflymentioned, by supporting the coil 48 at the side of pivot 42 that isopposite to the main frame 1 of the machine, main frame is more readilyand easily moved on the subframe since the weight on the subframe is toa substantial degree counterbalanced, and since the adjustment of themachine is usually made when there is a substantial coil on the machine,this is important.

Another advantage of the arrangement is that by drawing the strip aroundthe wheels 55, the stresses are substantially taken out of the flatstrip leading to the marginal forming rolls, provided the strip is keptunder tension when drawn around the wheels 55. This tension ismaintained by suspending the coil on drum 52 so that the greater weightof the coil is below the axis of the drum, and by drawing the strip fromthe lower side of the coil. This arrangement provides an automatic brakethat will maintain the length of the strip between the coil and theroller sets 2-4 under constant tension.

A further advantage of the arrangement of the coil, frame 1 and theparts on said frame is that the machine is more compact than where thesupply coil is at the feed end. Usually heretofore, in the latterstructure, the strip is drawn from the upper side of the coil, and asthe coil decreases in diameter the strip from the coil to the formingrollers changes direction or means must be provided to keep the stripstraight as the size of the coil decreases.

Rollers of sets 2, 3, 4

A common feature of the rollers 5-10 which make up the pairs 2, 3, 4 isthe formation of the portions of these rollers between their oppositeend portions.

Insofar as the rollers of sets 2, 3 are concerned, which are rollers 5,8 and 6, 9, their opposite end portions are conventional.

FIG. 12 is illustrative of the cross sectional contours of the ends of:the middle rollers 6, 9, or pair No. 3, in which the outer end portionof roller 6 (relative to frame 1) is formed with a radially outwardlyprojecting flange 75 that is adapted to enter a generally complementaryrecess 76 opposite thereto in lower roll 9, the latter being an annularoutwardly opening V-shaped recess, and the inner surface of the annularflange 75 being slanted to correspond to the axially inner side of theV.

The opposite end of roller 6 is formed with a radially outwardlyprojecting annular rib 77 having a slanted axially facing surface thatis directed generally toward the outer end of the roller. The end ofroller 9 that is opposed thereto is relieved as at 78 to receive the rib'77.

The first roller set No. 2, which consists of rollers 5, 8, havesubstantially the same structure, except that the ribs or flanges do notproject as far and the recesses that receive them are more shallow, andthe inclined surfaces are less steep.

Thus, as the strip passes between set No. 2 of rollers, the marginalportion of strip 20, which will ultimately be the flange 71 of FIG. 3,is slightly bent downwardly, and when it passes between the rollers 6, 9of set No. 3, the marginal portion will be further bent to the positionshown in FIG. 12.

At the same time, the channel 72 along the opposite marginal portion ofthe strip will be progressively formed, first by the rollers of set No.2, and then by the rollers 6, 9 of set 3, as seen in FIG. 12. Thismarginal forming structure is much the same as in US. Letters Patent No.1,288,134 issued December 17, 1918 to C. G. Naylor.

However, heretofore adjustment must be made for strips of differentgauges or thickness.

In the present instance, as seen in FIG. 1 and more in detail in FIG. 8,the intermediate or central portion of each roller is formed with a rowof spaced annular outwardly projecting ribs which may have fiat radiallyoutwardly facing surfaces. The ribs on the upper rollers 5, 6, 7 arestaggered relative to the ribs 81 on the lower rollers 8, 9, 10 andadjacent ribs 88, 81 are spaced axially of the rollers and the ribs orridges on one roller of each pair are in non-lapping relation, axiallyof said rollers, with the ribs or ridges on the other roller, so that arelatively heavy gauge strip will be sprung slightly between adjacentrollers 80 and adjacent rollers 81, while lighter gauge metal will bemerely tightly gripped by the rollers, without being sprung. This doesnot corrugate the strip, although in relatively heavy gauges there maybe a slight distortion or impres sion where the ribs 80, 81 engaged thestrip, which, however, appears only in the heaviest gauge metal themachine is intended to handle.

The advantage of providing a structure that is adapted to automaticallyand without adjustment handle metal strips of several gauges is believedto be obvious. This structure becomes more important when the structureof the rollers of set 4 or rollers 7, 18 are considered.

Rollers of set 4 0r final marginal forming rollers Referring to FIG. 13,the upper roller 7 is formed at its outer end with a coaxial threadedextension 82 on which is threadedly supported a channel forming annularring 83, which ring projects radially outwardly of the main body of theroller and into a relieved portion 84 at the outer end of the lowerroller 10.

The axially inwardly facing surface of the ring 83, which is the surfacethat faces toward frame 1, is inclined inwardly from its outerperipheral edge.

This ring 83 may be moved toward or away from the shoulder 85 that is atthe bend between the central body of strip 20 and the inner side of thechannel that is formed in the marginal portion of strip 20.

FIGS. 12 and 13 should be compared, since the channel portion of strip20 as seen in FIG. 12 is the shape it has when it reaches the rollers 7,10.

When said channel portion reaches the rollers 7, 10 the outer side 86 ofthe channel 72 will engage the slanted side of ring 83, as seen in FIG.13, and it will be bent a substantial distance past a vertical positionto a position that may be almost parallel to the inner side 87 of thechannel. However, this outer side 86 will spring back to a degree afterit leaves the rollers 7, 10 and the degree to which it will so spring isaccording to the characteristic of the metal and to the gauge of themetal.

By enabling the ring 83 to be quickly adjusted relative to the shoulder85 of the lower roller 10, the correct degree of bend of the outer side86 of the channel to compensate for the spring-back, can be readilydetermined. After the ring is in its adjusted position, a set screw 88is tightened to hold it in adjusted position.

At the flange forming end of the lower roller 10, a ring 89 similar toring 83 is threadedly supported a threaded portion 90 of the shaft ofroller 10. When the flange 71 of the strip 20 leaves the rollers 6, 9 ofthe middle set 3, it is substantially as seen in FIG. 12 and it must bebent a predetermined degree past a position in which it is at rightangles to said strip so it will spring back to a position such as seenin FIG. 5.

Ring 89 has an axially facing slanted surface that faces toward theouter end of the roller 10, and this slanted surface engages the flange71 and bends it toward the axially facing shoulder 91 of roller 10 thatis in spaced opposed relation to the slanted side of the ring 89. Byadjusting ring 89 on the threaded portion 90 of the shaft of rollers 18,the degree of bend of the flange 71 can be varied according to the gaugeof metal and the character of the latter. Set screw 96 locks ring 89.

In connection with the above, it may be pointed out that while the metalin a coil that is made is uniform in its resiliency for a particulargauge, it does not necessarily follow that another coil having the samespecifications will have exactly the same resilient characteristics.Hence the provision for rapid adjustability of the last pair of marginforming rollers, as above provided, is quite important.

Helix forming head and guide shoe The helix forming head, generallydesignated 40, comprises a pair of axially spaced, substantiallyhelically extending rods 92, 93, the rod 92 being the outermost rod ofthe helix and the rod 93 being the innermost rod (FIG. '2). This pair ofrods preferably have cylindrical opposed surfaces that define theopposite sides of a helically extending passageway or path 94 that opensgenerally oppositely outwardly at its ends so that the one outwardlyopening end faces the oncoming flange 71 of strip 20 after the strippasses the No. 3 pair of rollers.

The opposite open end of the passageway 94 is directed toward the spacebetween the seam locking rollers 27, 29 (FIG. 3). The helix extendsabove the seam locking rollers. The end of the head 40 that faces towardthe oncoming flange 71 may be called the inlet end of the head, whilethe opposite end is the outlet end.

The rod 92, for most of its length, is offset relative to the rod 93commencing at the inlet end of the head in a direction axially of thehelix toward the outlet end (FIGS. 9-l0) and it may, at the outlet end,be disposed substantially below rod 93 (FIG. l-l). However, at theinitial length of the rods, the juncture of the flange 71 and the mainbody of the strip will be between the rods 92, 93. As the strip isdriven into passageway 94 between the rods, the rod 93 will force theflange and the portion of the strip therealong to a helical path definedby the radially inwardly facing surface of the outer rod 93. The rod 93will prevent the flange from moving straight, since the juncture betweenthe flange and strip engages the inner surface of said rod above thelowermost point on the latter.

Once the flange is bent in the proper direction it will automaticallyfollow a helical path, and will emerge from the outlet headed toward thespace between the seam locking rollers 27 29.

In order to insure against the possible drifting of the flange out ofthe helical path leading to the outlet, a third rod 95 is rigidlysecured to the rods 92, 93 in spaced horizontally opposed relation tothe rod 92, so as to extend across the outer surface of flange 71 (FIGS.10, M). This third rod or flange engaging rod may extend from a pointabout half way around the rods to approximately the outlet end of thepath.

The rods 92, 93 and 95 are held together in spaced relation by anysuitable connectors 98 that clear the flange 71 as the latter is carriedaround the helix.

After the flange 71 has passed out of the outlet end of the passagewayor path 94, it passes below a guide shoe 99 (FIGS. 4, in engagement withthe generally downwardly facing convex surface of said shoe, whichsurface terminates substantially at the space between locking rollers27, 29. The shoe positively guides the flange 71 into the upwardlyopening channel '72 of strip 20 that, in turn, is guided between theseam locking rollers 27, 29 below a horizontal guide plate 100 that isbelow and in rearward extension of shoe 99 (FIG. 5).

The shoe 99 and guide plate 100 may be welded or otherwise securedtogether, and, as seen in FIG. 5 and FIGS. 16, 17, the shoe projectslaterally of the plate 100 and the underside of said shoe along the freelateral edge thereof on the laterally projecting part may be convexlycurved, which curved surface contributes to guiding the flange 71 to itsproper position for entering channel '72. The end of the shoe thatextends between the rollers 27, 29 terminates as close as possible to avertical line extending betwen the axes of said rollers.

As seen in FIG. 1, a plate 101 secured to frame 1 by bolts 102 andextending through slots 103 in said frame carries the guide shoe 99 andplate 100. This plate 101 may be thus adjusted longitudinally of theframe 1 to properly position the shoe 99.

Seam locking rollers The rollers 27, 28, 29 and 30, as seen in FIG. 3,are arranged so that rollers 28, 29 and 30 are on shaft 33 while roller27 is keyed to shaft 32. Shafts 32, 33 are positioned with their axes inthe same vertical plane.

Where there is a change in the gauge of metal that is being used for thepipe, the rollers 2830 would be changed. The thinner the metal thegreater the diameters of rollers 28-30.

As seen in FIG. 3 there is a space between the outer peripheries of therollers 27, 29 in which the flange 71 and channel 72 will pass.

The spacing between rollers 27 29 is such that the flange 71 and thesides of channel 72 will be pressed tightly to gether (FIG. 3), andsince the outer peripheries of rollers 27, 28, 30 engage the strip 20 atopposite sides of the seam, with roller 29 being of reduced diameter,the seam '73 will not project into the pipe but will be whollypositioned outside the pipe (FIG. 7) leaving the inside of the pipeunobstructed by the seam.

Rollers 28, 29, 30 are on separate bearings since they may rotate atdifferent peripheral rates of speed. The fact that shaft 33 is driven inthe same direction as the rollers facilitates their rotation.

Once a complete starting helix is formed in strip 20 and the seam islocked, the outer rod 92 functions mainly to prevent radial outwardexpansion of the flanged por tion of the strip. The pipe will be formedmore or less automatically. In the helix forming head, the outer rod 92,at the start of the formation of a helix in the strip must control thediameter of the pipe and the flange 71 must be started in the truedesired spiral and accurately guided into the channel 72 at the outletend of the head.

To change the diameter of .a pipe it is merely necessary to remove thetwo bolts holding the head in place and substitute a head of the desireddiameter, which may be accomplished in a few minutes time.

It should also be noted that the locking of the seam is accomplished ata point along a line that is at a right angle to the longitudinal axisof the strip 20, said line being parallel with the axis of rollers28-30. The strip is not fed to the seam locking rollers at an obliqueangle, hence all of the rollers including the seam locking rollersrotate about parallel axes.

Attention is called to the fact that the roller 29 is formed with anannular outwardly projecting flange 104 along the side of the rollerthat is adjacent to the outer end roller 28.

Where a heavier gauge metal than that illustrated is being used for thepipe, this flange would be of greater axial thickness or may even beeliminated for the heaviest gauge metal that the machine is adapted tohandle. Where lighter gauge metal is being used it may be thicker asseen in FIG. 18. The thickness of the flange determines the axial widthof the space in which the flange 71 and channel 72 extend, and thiswidth is such as to insure the tightest possible seam. If the same axialdimension of the space were used for all gauges of metal, then the seamwould not be as tight as it should be since the axially opposed surfacesdefining width of the space in which the seam is formed would notaxially crowd the metal of the flange and channel together in thelighter gauge metals to insure a tight seam. However, by varying thethickness of the flange 104, the axial dimension of the space betweenflange 104 and roller 30 may be varied. Of course, the outer diameter ofthe portion of roller 29 at the side of flange 104 would be greater(FIG. 8) where metal of lighter gauge is being used, or it would be lesswhere the gauge is heavier.

It should be noted that the outer periphery of flange 104 will notnecessarily be in driving relation with strip 20. The mounting of theroller 29 on a bushing separate from the bushings supporting the rollers28, 30 enables a differential in the rate of rotation of the rollers2830.

In conclusion it has been mentioned, with reference to the helix forminghead 40, that suitable bolt holes are provided in the frame for securingdifferent helix forming heads to frame 1. The same bolts in the sameplaces are employed where the strip that forms the diiferent diameterpipe is of the same width. It is only when a wider strip is used thatthere is any occasion to employ a diflerent bolt hole.

I claim:

1. In a machine for forming helical lock seam pipe from a continuoussheet metal strip and which machine includes;

(a) strip moving means for moving said strip generally horizontallylongitudinally thereof in one direction, and

(b) flange forming means for forming a downwardly projecting flangealong one marginal portion of said strip during said movement, and

(c) channel forming means for forming an upwardly opening channel alongthe other marginal portion of said strip during said movement, whichchannel is adapted to receive said flange therein when said strip ishelically formed;

(d) a pair of helically extending rods one spaced radially within theother to provide an inner helical rod and an outer helical rod;

(e) said rods defining substantially a single coil of a helix about ahorizontal axis with their terminating ends lowermost and at pointsspaced horizontally apart a distance substantially equal to the distancebetween said flange and channel;

(f) the space between said rods opening oppositely outwardly at theterminating ends of said helix; and

(g) means supporting said helix of rods with its axis above the path oftravel of said strip and at right angles to the direction of movement ofthe latter and with the outwardly opening space between said rods at oneend of said pair thereof facing oppositely to the direction of movementof said strip and substantially in alignment with said flange forreceiving the portion of said strip along said flange between said rods,and with the outwardly opening space between said rods at their oppositeends fac ing the direction of movement of said strip and adjacent to andover the said channel,

(h) said outer helical rod being slightly offset relative to said innerhelical rod axially of the helix at said one end of said pair of rodstoward the edge of said strip having the channel therein to support thejuncture between said flange and said strip against said inner helicalmember for following the said inner helical member to thereby form saidflange into a helix and to guide the latter into the open side of saidchannel during said movement of said strip.

2. In a machine as defined in claim 1;

(i) rod holding means at opposite ends of said pair of rods holding themrigidly relative to each other in their spaced relation,

(j) and means for removably securing said rod holding means on saidmachine in said position for forming said strip to a helix.

3. A head for use on a helical lock seam pipe forming machine to form ahelix from a strip of sheet metal that is preformed along one marginalportion thereof to provide a flange projecting to one side of said stripand that is preformed to provide a channel along the other marginalportion opening outwardly of the side of said strip opposite to said oneside having a main body portion between said flange and channel, saidhead comprising:

(a) a pair of helically extending rods one spaced radially within theother a distance adapted to receive said strip along such flange therebyproviding an inner rod and an outer rod;

(b) said rods defining substantially a single coil of a helix with thespace between opposite terminating ends of said rods opening outwardlyin generally opposite directions substantially tangentially of saidhelix,

(0) the adjacent surfaces of said rods being substantially cylindricaland one laterally facing surface of said outer rod directed axially ofsaid helix and away from the body portion of said strip being free fromobstruction to engagement with the side of said flange adjacent to saidbody portion when said strip adjacent to said flange is between saidpair of rods,

((1) said rods being slightly offset relative to each other axially ofsaid helix to engage said strip along the juncture between said flangeand said strip and to bend said flange to follow a helical path uponmoving said strip longitudinally thereof around said helix with saidstrip along the juncture between said flange and said strip disposed inthe space between said rods.

4. In a machine for forming helical lock seam pipe from a continuousflat sheet metal strip;

(a) a pair of parallel rollers alongside each other between which saidstrip is adapted to be moved longitudinally of the latter,

(b) means supporting said rollers for frictional engagement withopposite sides of said strip between its marginal portions and forrotation of said rollers to so move said strip;

(c) an annular bending member on one end of one roller of said paircoaxial therewith and (d) an annular bending member on the end of theother member of said pair at the end thereof that is opposite to saidone end,

(c) said means supporting said rollers for frictional engagement withopposite sides of said strip including shafts extending from one of thecorresponding ends of said rollers,

(f) said bending members each being formed with an axially facingsurface adapted to engage said strip along its opposite marginalportions for engaging and bending said marginal portions generallyaxially;

(g) each roller including a threaded end portion threadedly supportingeach annular bending member on the roller carrying the same for axialmovement to different adjusted positions on each roller relative to theportion of the roller that is adapted to engage opposite sides of saidstrip upon rotation of each annular bending member in one direction orthe other relative to the roller carrying the same to thereby eflect agreater or lesser degree of bend of said marginal portions of said stripaccording to the gauge of the metal of said strip, and

(h) means for securing said annular members in their said adjustedpositions for rotation with said rollers.

5. A construction as defined in claim 4, plus;

(i) the portions of said rollers that are adapted to frictionally engagethe opposite sides of said strip being formed with annular axiallyspaced ridges in spaced staggered relation for so engaging said oppositesides of said sheet along axially spaced lines with the ridges on oneroller of said pair in nonlapping relation, axially of said rollers, tothe ridges on the other pair thereby enabling metal strips of differentgauges to be driven by and between said rollers without changing thespacing between said pair of rollers and without material distortion ofthe flat portion of said strip between its marginal portions.

6. A machine for forming a helical lock seam pipe (a) a horizontallyextending main frame;

(b) a plurality of pairs of horizontally disposed superposedstrip-driving and marginal bending rollers horizontally spaced apart ina horizontally extending row adapted to receive a fiat strip at a feedend of said row and to drive said strip longitudinally thereof to theopposite helix forming end of said row;

(c) said rollers having marginal bending means thereon at their oppositeends adapted to form opposite marginal portions of said strip forinterlocking when said strip is helically formed with one preformedmarginal portion in lapping relation to the other preformed marginalportion,

(d) a helix forming head on said frame at said helix forming end of saidrow, said head comprising: (e) a pair of substantially parallel rodsbent to form a single helix with one rod generally spaced radiallyinwardly of the other rod a sufficient distance to receive therebetweenthe portion of said sheet along one of said marginal portions only andsaid other rod being adapted to engage and to guide one of saidpreformed marginal portions around the helix formed by said rods to saidposition in lapping rela tion to the other marginal portion,

(f) means removably supporting said pair of rods on said frame in aposition relative to the pair of said rollers adjacent thereto forreceiving in said space at one of the ends of said pair of rods said oneof said preformed marginal portions;

(g) a pair of presser rollers supported on said frame for rotation aboutan axis parallel with the axes of the rollers of said row and at rightangles to the longitudinal axis of said strip,

(h) said pair of presser rollers being supported on said frame adjacentto the said helix forming head in a position for receiving the lappingmarginal por tions of said strip therebetween and means supporting themfor pressing said preformed lapping marginal portions in tightinterlocked relation,

(i) a subfrarne below said main frame,

(3') and a pivot connecting said main frame with said subframe on a lineextending perpendicular to the axes of said presser rollers andextending through said last mentioned axes and the preformed lappingmarginal portions of said strip Where said pressing rollers force saidpreformed lapping marginal portions together.

7. A machine as defined in claim 6;

(k) coil supporting means on said frame for supporting a supply of saidstrip in the form of a coil thereof at the side of said pivot oppositeto the side on which said row of rollers are positioned whereby theweight of said coil will partially balance the weight of said rollers tofacilitatepivotal movement of said frame on said subframe;

(l) and guide means at the feed end of said machine for guiding saidstrip from a coil on said coil supporting means to the pair of rollersat the feed end of the row thereof and for supporting the portion ofsaid strip between said coil supporting means and said last mentionedpair of rollers.

8. A machine for forming a helical lock seam pipe from a continuoussheet metal strip that comprises the combination of:

(a) a horizontally elongated main frame;

(b) a plurality of pairs of horizontally disposed superposedstrip-driving and marginal bending rollers horizontally spaced apart ina horizontally extending row adapted to receive a fiat strip at a feedend of said row and to drive said strip longitudinally thereof to theopposite helix forming end of said row;

(c) said rollers having marginal bending means thereon at their oppositeends adapted to form opposite marginal portions of said strip forinterlocking when said strip is helically formed with one preformedmarginal portion in lapping relation to the other preformed marginalportion,

((1) a helix forming head on said frame at said helix forming end ofsaid row adapted to receive and to guide one of said preformed marginalportions in a helical path to said lapping relation to the otherpreformed marginal portion,

(e) means on said frame below said helix forming head for pressing saidpreformed lapping marginal portions into interlocking relation,

(f) a portion of said frame extending longitudinally thereof past saidhelix forming head to the side of said head that is opposite to said rowof rollers,

(g) a coil supporting roller having annular radially outwardlyprojecting heads at its end rotatably carried on said extension forrotation about a horizontal axis for supporting a supply of said stripin the form of a coil having a relatively large diameter central core;with the central axis of such coil spaced below the axis of said coilsupporting roller,

(h) a pair of concentric marginal supporting wheels rotatably supportedon said frame adjacent to the feed end of said row over which a lengthof such strip from the lower side of a coil adapted to be supported onsaid coil supporting roller is adapted to extend with the marginalportions of such strip extending around and over said wheels to betweenthe rollers at the feed end of said row whereby the length of such stripadapted to extend between such coil and the feed end of said row willform a U- bend in passing over said marginal supporting wheels torelieve tension in said length prior to bending by such bending means.

9. In the combination as defined in claim 8,

(i) means supporting one of said marginal supporting wheels for movementtoward the other to adapt said wheels to support a strip of reducedwidth, and

(j) an annular ring of an internal diameter greater than the diameter ofsaid one of said heads adapted to be slipped over said one of said headsand onto said coil supporting roller without removing said roller foradapting said coil supporting roller to a coil of a metal strip of saidreduced width.

10. In a machine for forming helical lock seam pipe from a continuoussheet metal strip and which machine includes a frame supporting means topreform opposite marginal portions of said strip to the same side ofsaid strip for interlocking when said strip is helically formed with onepreformed marginal portion in overlying relation to the other,

(a) a helix forming head on said frame in a position to receive said oneof said preformed marginal portions upon movement of said strip theretolongitudinally of said strip and to guide said one of said preformedmarginal portions to helical form and to interlocking relation with theother of said preformed marginal portions,

( b) flattening means on said frame adjacent to said helix forming headin a position to receive said preformed marginal portions after they arein interlocking relation, said flattening means comprising:

(0) a central roller and a pair of end rollers coaxial therewith, eachrotatably supported on a shaft for rotation independently of the othersabout the axis of the latter, said central roller being of less externaldiameter than the external diameters of the two end rollers and said endrollers being of the same diameter,

(d) a drive roller supported on said frame for rotamovement of saidstrip longitudinally thereof thereby causing said strip including saidflange and said channel to form a helix at said helical path;

() leaving the remainder of said strip extending transversely of saidstrip away from said flange and the portion adjacent thereto, free fromall support and engagement with any external object other than alongsaid flange, during said movement of said flange along said helicalpath, and

(d) guiding said leading end of said flange into said channel at the endof said helical path in the direction of movement of said flange, intosaid channel for securement therein.

pressed together in looking relation when the portions of the adjacentsections of said strip at opposite sides of the interlocking marginalportions are flat between the peripheries of said end rollers and saiddrive roller,

(e) said drive roller being adapted to be positioned inside the helix ofsaid strip whereby the entire seam 15 will :be outside the inner surfaceof the pipe thereby leaving the inner surface of said pipe free frompro- References Cited by the Examiner UNITED STATES PATENTS jecfions183,328 10/1876 Root 113-35 199,631 1/1878 Felix et a1. 24273 T methodof g a hehcal, 10ck Seam P P 1 394 11 10 1921 Rendano 113 35 from acontinuous strip of sheet metal moving longitu- 1856151 5/1932 B1 OS ta] 153 73 dinally thereof in one direction along -a path of travel s e n2,03 8,483 4/ 1936 Ferguson et al 113-35 with one end leading, thatincludes the steps of.

(a) bending one longitudinally extending margina 2136942 11/1938 Freeze11335 ortion of said stri to one side thereof to form a 2282176 5/1942Fay et a1 11335 ontinuous flange, commencing with said leading g endand, at the same time bending the other lonme en u gitudinally extendingmarginal portion of said strip FOREIGN PATENTS to form a continuouschannel openlng outwardly of 2 said strip to the side of the latter thatis opposite to 41513 1 189 3 Great i i Said flange; 869,390 5/ 1961Great Britain.

(b) confining the portion of said strip along said flange only,commencing with said leading end, to between helically extendingsurfaces defining the sides of a predetermined helical path of travelduring said CHARLES W. LANHAM, Primary Examiner.

NEDWIN BERGER, Examiner,

1. IN A MACHINE FOR FORMING HELICAL LOCK SEAM PIPE FROM A CONTINUOUSSHEET METAL STRIP AND WHICH MACHINE INCLUDES: (A) A STRIP MOVING MEANSFOR MOVING SAID STRIP GENERALLY HORIZONTALLY LONGITUDINALLY THEREOF INONE DIRECTION, AND (B) FLANGE FORMING MEANS FOR FORMING A DOWNWARDLYPROJECTING FLANGE ALONG ONE MARGINAL PORTION OF SAID STRIP DURING SAIDMOVEMENT, AND (C) CHANNEL FORMING MEANS FOR A UPWARDLY OPENING CHANNELALONG THE OTHER MARGINAL PORTION OF SAID STRIP DURING SAID MOVEMENT,WHICH CHANNEL IS ADAPTED TO RECEIVE SAID FLANGE THEREIN WHEN SAID STRIPIS HELICALLY FORMED; (D) A PAIR OF HELICALLY EXTENDING ROD ONE SPACEDRADIALLY WITHIN THE OTHER TO PROVIDE AN INNER HELICAL ROD AND AN OUTERHELICAL ROD; (E) SAID RODS DEFINING SUBSTANTIALLY A SINGLE COIL OF AHELIX ABOUT A HORIZONTAL AXIS WITH THEIR TERMINATING ENDS LOWERMOST ANDAT POINTS SPACED HORIZONTALLY APART A DISTANCE SUBSTANTIALLY EQUAL TOTHE DISTANCE BETWEEN SAID FLANGE AND CHANNEL; (F) THE SPACE BETWEEN SAIDRODS OPENING OPPOSITELY OUTWARDLY AT THE TERMINATING ENDS OF SAID HELIX;AND (G) MEANS SUPPORTING SAID HELIX OF RODS WITH ITS AXIS ABOVE THE PATHOF TRAVEL OF SAID STRIP AND AT RIGHT ANGLES TO THE DIRECTION OF MOVEMENTOF THE LATTER AND WITH OUTWARDLY OPENING SPACE BETWEEN SAID RODS AT ONEEND OF SAID PAIR THEREOF FACING OPPOSITELY TO THE DIRECTION OF MOVEMENTOF SAID STRIP AND STUBSTANTIALLY IN ALIGNMENT WITH SAID FLANGE FORRECEIVING THE PORTION OF SAID STRIP ALONG SAID FLANGE BETWEEN SAID RODS,AND WITH THE OUTWARDLY OPENING SPACE BETWEEN SAID RODS AT THEIR OPPOSITEENDS FACING THE DIRECTION OF MOVEMENT OF SAID STRIP AND ADJACENT TO ANDOVER THE SAID CHANNEL, (H) SAID OUTER HELICAL ROD BEING SLIGHTLY OFFSETRELATIVE TO SAID INNER HELICAL ROD AXIALLY OF THE HELIX AT SAID ONE ENDOF SAID PAIR OF RODS TOWARD THE EDGE OF SAID STRIP HAVING THE CHANNELTHEREIN TO SUPPORT THE JUNCTURE BETWEEN SAID FLANGE AND SAID STRIPAGAINST SAID INNER HELICAL MEMBER FOR FLOWING THE SAID INNER HELICALMEMBER TO THEREBY FORM SAID FLANGE INTO A HELIX AND TO GUIDE THE LATTERINTO THE OPEN SIDE OF SAID CHANNEL DURING SAID MOVEMENT OF SAID STRIP.